Cam Chain Tensioner

Hey All,

Took the valve cover off to check the valve clearances. While off, I rotated the crank. When done, I reinstalled the valve cover and couldn't figure out why it would not meet the head without having to push down a little. It seemed like the cam chain guide located in the valve cover had moved. I checked and it hadn't, so I figured that it must be normal, just never noticed in the past.

Well, after riding for the last 30 miles it finally struck me that the cam chain tensioner had taken up the small slack that was normally provided by the upper guide in the valve cover when I rotated the crank with the valve cover removed. Now, with the valve cover reinstalled, the attached upper guide was pressing down on a straight and tight cam chain.

QUESTION: If I leave alone, will the cam chain guides be destroyed? It wasn't much of an interference, only about 1/8 inch that I had to press down to reinstall the valve cover. Please advice, TY.

You need to slacken off the tensioner and let it re-adjust under it's own pressure.
You are risking serious damage to the guides and could even snap the camchain if you run as is.

Hi Zed,

I removed the 17mm cap and pulled the spring with stop pin. Then rotated that crankshaft with wrench and reinserted the stop pin. Manual says that it should stick out 7.5mm, but is slides almost all the way in with only 1mm showing. When I slowly turn the crankshaft it stays in. I trust that the cam chain is not stretched because when I installed the head I noticed that the arrows on the cam sprockets lined up perfectly with the head and the number of links (44?) were correct.
I guess maybe the chain guides might be worn? I did run the bike for about 40 miles with the tensioner in the previous state. I worry that the tensioner is now almost completely extended and not able to provide much tension to the chain. Please let me know your thoughts, thanks.

Even though you have removed the cap and wedged pin which should release the tension on the chain I would fully remove the tensioner to ensure there is no way it is sticking in an extended state (do not rotate the crank with the tensioner removed).
Once free movement is confirmed, re-fit the tensioner and re-check the length of pin protrusion.
If it is still under the manuals spec and the tensioner is near its limit there is either significant wear on the chain guides/slippers and/or camchain stretch and the only solution will be to replace these components.

Thanks for your time Zed. I checked the upper cam guide mounted in the valve cover and it measures well within spec, Also, I have measured the cam chain and it appears to be dead on at - 127 mm between 20 links. So, barring extreme wear on the main tensioning guide, everything should be okay. I just wish the main tensioner spring was more compressed on the push rod when it contacts main the tensioning guide (more tension!) and not extended out to what appears to be almost its limit (less tension).